Trove of new horror species discovered in Australian abyss

A peanut worm, of the phylum Sipuncula, shrinks when threatened. Ironically, it can reproduce asexually.

Rob Zugaro

What lurks in the ocean’s abyssal depths? That was the question the crew of research vessel RV Investigator sought to answer in a month-long expedition exploring Australia’s eastern abyss for the first time.

“The abyss is the largest and deepest habitat on the planet, covering half the world’s oceans and one third of Australia’s territory, but it remains the most unexplored environment on Earth,” said Museums Victoria senior curator Tim O’Hara on the voyage’s departure.

At 4,000 metres down in the ocean, the abyssopelagic zone has been difficult to explore. It is so deep no light can penetrate it, and consequently extremely cold. Moreover, the pressure at that depth is crushing. So far, only a small number of samples have been collected from Australia’s abyss — but there is much to learn from them.

“The data gathered on this trip will be crucial to understanding Australia’s deep-sea habitats, their biodiversity and the ecological processes that sustain them. This will assist in its conservation and management and help to protect it from the impacts of climate change, pollution and other human activity,” O’Hara said.

Using multibeam sonar, the team mapped the abyss floor, which allowed them to send collecting gear such as trawling sleds down without smashing it into rocks. And they brought back a treasure trove of over 1,000 different species of deep-sea creepy crawlies, over a third of which are completely new to science.

And, being abyssal creatures adapted to survive in the crushing, freezing darkness, they are pretty grotesque to our land-dwelling human eyes — slimy and toothy and luminescent and, in one very memorable case, more than a little bit phallic.

The team also found a worrying amount of pollution.

“We have found highly concerning levels of rubbish on the sea floor,” O’ Hara said. “We’re 100 kilometres off Australia’s coast, and have found PVC pipes, cans of paints, bottles, beer cans, woodchips, and other debris from the days when steamships plied our waters. The seafloor has 200 years of rubbish on it. Hopefully information such as this is the first step in influencing social attitudes towards rubbish disposal.”